1. Technical Field
The invention relates to a process for the establishment virtual connections passing through switching matrices of a multi-stage switching system.
2. Description of the Prior Art
A process for the establishment of virtual connections of this kind is already known from U.S. Pat. 4,491,945. In this conventional process, a call packet arriving at one of the inputs of the switching system, in which the establishment of a virtual connection is requested, is conducted directly to a switching matrix input which is assigned to the input at which the packet arrives. In this case, the call packet contains as its header a virtual channel number which designates the virtual connection to be established and, in its information part, the destination address for the said connection. On the basis of this destination address, a processor assigned to the switching matrix in question determines the switching matrix output to be used for the establishment of the connection and a virtual channel number that is valid for this output. This virtual channel number is used to transmit the message packets that follow the call packet, through the output that has been determined.
The information described above is stored, under control of the processor, in a memory assigned to the above-mentioned input of the switching matrix. Next, this processor generates a call packet corresponding to the previously received call packet, whose header contains the previously determined virtual channel number and transfers it over the previously defined output to the following switching matrix. In this switching matrix and the switching matrices that follow it, procedures take place that correspond to the procedures explained above, so that ultimately the connection information described above is stored successively in all the switching matrices of the switching system that are to be included in the virtual connection that is to be established.
It is the object of the invention to provide a method using a process of the kind described above to determine, with a minimum of control operations, the connection information that is required for the establishment of a virtual connection and to store it in the individual switching matrices that are involved in that virtual connection.